Backing up computers is an important task in the everyday operation of computer systems. Backup may be required for retrieval of information in cases of human errors, technical failures, upgrades, or the like, as well as for legal or operational reasons.
Traditionally, tapes were used for storing large amounts of computer data. Tapes are reliable and are considered environmentally friendly, i.e., do not waste energy, unlike disks that spin constantly and consume energy. However, tapes have some significant drawbacks. For example, they take up a lot of physical space, and retrieving data from tapes may take a long time, for example in the order of magnitude of minutes, as compared to milliseconds in disks.
In addition, handling tapes necessitates manual labor. For example, operations such as making copies of tapes have to be done manually, creating backups at off-site locations cannot be performed without physically transporting them, or the like.
Further, when keeping data on tapes for long periods of time, such as years or decades, supporting tape drives have to be maintained in order to retrieve data from the tape when required. This drawback also implies that upgrading the used tape drive technology may be a complex operation.
Object storage, also referred to as object-based storage, is a computer data storage architecture that manages data in the form of objects, as opposed to other storage architectures such as Count key data (CKD) storage currently used by mainframe systems, or file systems. Each object typically includes metadata, the data itself, and a globally unique identifier. Object storage provides capabilities not addressed by other storage architectures, such as interfaces that can be programmable by an application developer as part of the application development, a namespace that can span multiple instances of physical hardware, data-management functions such as data replication and data distribution at object-level granularity, or others. Object-storage systems allow retention of massive amounts of unstructured data, and is thus used, inter alia, for purposes such as storing photos, songs, or files in online collaboration services. Object storage is gaining popularity in the backup arena on open systems. Object storage, as the name suggests, stores objects, and before creating a new object, for example when backing up data, needs to a-priori know the size of the object.
Due to inherent limitations, mainframe (MF) computers still use tapes for backup, and are thus deprived from enjoying the advantages of modern storage systems.